Dining establishments can nudge consumers to eat less meat by offering more vegetarian choices, according to a study of university-cafeteria sales.

Emma Garnett and her colleagues at the University of Cambridge, UK, collected data on more than 94,000 meals sold in 3 of the cafeterias at the university in 2017. When the proportion of meatless options doubled from one to two of four choices, overall sales remained about constant. But sales of meat-containing meals dropped, and sales of vegetarian meals, such as “wild mushroom, roasted butternut squash and sun blushed tomato risotto with parmesan”, rose 40–80%.

Increases in plant-based dining were largest among people with the lowest baseline rates of vegetarian-meal consumption. The researchers found no evidence that higher sales of vegetarian dishes at lunch led to lower vegetarian sales at dinner.

Other variables that influenced dining choices included the relative prices of vegetarian and non-vegetarian options, and the outdoor temperature.

The authors suggest that an increase in vegetarian options could encourage consumers to move away from meat-heavy diets, potentially reducing greenhouse-gas emissions linked to animal-derived food.